Septic tank



Sept. 20, E949- G. L.. LOELKES 2,482,353

l SEPTIC TANK Filed June 2l,- 1946 Patented Sept. 20, 1949 UNITED STATES PATENT orrlcr.

sEPTIo TANK George L. Loelkes, Maplewood, Mo., assignor to Blackmer and Post Pipe Company, St. Louis, Mo., a corporation of Missouri Application June 21, 1946, Serial N0. 678,427

4 Claims. 1

The present invention relates to a septic tank.

It is an object of the invention to provide a septic tank that is most effective by virtue of having a desirable shape, liquid capacity, and operation. l A further object of the invention is to provide a septic tank that may be easily installed and which will be effective inoperation to a degree greater than those now in use. A particular object is to provide a tank having improved flow-through characteristics, with better circulation and more uniform time of dwell.

A further object of the invention is to provide a septic tank that may be easily built up, and which, With a minimum of installation diiculties, will have a maximum of liquid capacity. A particular object is to provide a septic tank that has adequate depth without requiring too great a hole for its installation. v

A'specic object of the inventionis to provide a septic tank that may be made of stock parts, such as sewer pipe sections, and yet which will obtain the advantages commonly associated with septic tanks especially built for this use. More particularly, it is an object to provide a septic tank made up of sewer pipe sections that has the iiow characteristics of a tank twice as long as it is wide.

An especial object is to provide a septic tank, and particularly one made of pipe sections, havingr desirable sludge area, but with deep circulation, even flow, improved velocity control, and reduced short circuiting. 4

Other objects will appear in the description to :f olow. e

In the drawings:

Fig. 1 is a side elevation of a septic tank made in accordance with the present design;

Fig. 2is a vertical section through the septic tank of Fig. 1; and

Fig. 3 is a horizontal section taken through the axis of the upper connecting pipe, looking downwardly, this viewbeing on a somewhat smaller scale.

The present septic tank includes two main chambers, generally indicated at I and I I. The chamber IQ is made up of a lower cylindrical tile I2 and an upper such tile I3, the two being connected together by duly tight bell and spigot connections, as shown.

The tank Il) has tted glazed parts making a cylindrical bottom, which, when cemented together by use of a jointing compound, forms a solid bottom I4, and it has a removable top I5 that may be intertted with the bell at the top of the section I3. An inlet or influent pipe I6,

2 from the house or other building to be connected with the septic tank, is provided.v Within the chamber It, this inlet line Iii has a T Il providing openings both upwardly and downwardly into the chamber IQ.

The chamber II is made up of a lower cylindrical pipe section 2l) and an upper section2l, iitted together by bell and spigot connections-as shown, this connection beingr duly tight. The tank I I likewise has tted glazed parts making a cylindrical bottom, which, when cemented together by use of a jointing compound, forms a bottom 22, like the previously mentioned bottom |11, and a removable top 23. An outlet pipe 24 leads from the tank l I, and, at its inner end, has a T 25 that opens upwardly and downwardly.

The two pipe sections I 9. and 2d of the two chambers I@ and iI, respectively, are connected by a connecting pipe 2S; whereas the two upper sections I3 and 2l are connected by a pipe 2l.

It will be observed that the four pipe sections I2, I3, 2B and 2l are conventional sewer pipe sec'- tions, cut only for the inlet, the outlet, and the connecting pipes. Also, the sections i3 and 2| are identical, as are the sections I2 and 28.

The sections I2, I3, 2l! and 2l preferably are approximately as wide as they are deep. That is to say, the chambers are twice as long, as wide, in the direction of flow. This meets desirable standards for effective function. The construction also permits the use of a tank that is at least four feet deep, as, for an average size dwelling, the two chambers will be two and onehalf feet in diameter.

Operation For any proper septic tank action, there must be a certain maximum velocity oi flow-through, and a certain minimum detention period of the sewage in the tank. Horizontal tanks have been made following the rule of length equals twice .the width. They reduce the velocity and control the detention period by such shape. In a deep tank of narrow horizontal section, there is a tendency to short circuit from the inlet to the outlet, so that, even when sedimentation is satisfactory, the liquid phase passes across from the inlet to the outlet without suicient dwell to permit proper anaerobic action. The present tank, by its flow course, follows the rule of length equals twice the width, in a vertical arrangement.

In the present septic tank, the total tank sizei. e., volume of the two chambers l0 and II is determined for the particular use. A conventional rule of thumb allows gallons per day per person. With thirty-inch pipe, the four pipe sections shown in the two chambers will afford this volume. If larger capacity is desired, the chambers may be larger or deeper; but preferably more than two chambers I and II are used, the additional chambers being connected by pipes 2S and 21 after the chamber I I, with the outlet leading from the last.

The inuent material received in the inlet is caused to course downwardly by the T I1. The main sedimentation occurs in the chamber I0. The solid material descends to the bottom, where it contributes to the anaerobic action. The liquidV courses primarily through the lower connecting pipe 2B, which is located above the bottom of the tank. The elevation of the pipe 26 is suicientto allow adequate sedimentation space, which is calculated for both chambers by established formulas. The pipe is as low as may provide such space, as the flow characteristics are better when deep.

The flow courses downwardly from the T I1, being baffled thereby against short circuiting to the connecting pipe 21. sedimentationV having largely taken place in the chamber I0, the liquid phase then passes through the connecting pipe '26 to the chamber I I. Therein any further necessary sedimentation takes place, whilerthe liquid phase passes upwardly toward the outlet T 25, which likewise is arranged to inhibit short circuiting. The anaerobic action continues in the chamber II. The two chambers aiord adequate dwell for this bacterial effect to be as complete as is required of septic tanks. The liquid phase, comprising water, dissolved materials and suspended materials largely colloidal, is then delivered to proper secondary treatment means.

In the event the sedimentation well of the rst chamber II! becomes full, the velocity toward the pipe 2e may be somewhat speeded across the surface of the sedimentation, discharging solid material into the sedimentation well of the chamber Il below the pipe 26. y

The pipe 21 between the top sections has two functions, in preventing overflow of the chamber I0 should the lower pipe 26 become obstructed, and in relieving excess pressure conditions in the chamber IEB by establishing a balance of liquid level in the two chambers, with consequent reduction in velocity of normal flow. To be most effective, this pipe 21 is located just below the liquid line.

The inlet I6 is shown as being at the same level as the outlet, to enable the pipe sections I3 and 2| to be identical. Functionally the inlet may be above the outlet. The connecting pipe 21 is preferably somewhat larger than the inlet, to assure its capacity to conduct any volume of inuent material freely.

. The liquid level is determined by the outlet. Above it may be a scum line, through which the Ts I'I and 25 open for pressure relief. These Ts prevent the Vscum from entering the inlet and outlet.

It will be seen that this septic tank may be made of stock pipe sections, and yet it provides superior operation, with improved flowcharacteristics and insured dwell, brought about by the deep flow course, well bailled. There is a minimum of short circuiting, a better ability to reduce velocity, improved sedimentation, and improved bacterial action.

What is claimed is:

1. In a septic tank, a pair of vertical chambers, the chambers providing a free ow path from top to bottom of each, each being at least substantially twice as deep as'it is wide, means closing the top of each chamber with a removable but relatively tight closure, an inlet into the upper part of the rst chamber, an outlet from the upper part of the second chamber, the outlet determining a liquid level for the system, a rst connection adjacent but above the bottom of the rst chamber that leads into the Second chamber adjacent but above the bottom of the second chamber, the. space in each chamber below said con- Y nection comprisinga sedimentation well, the two chambers and the connection establishing a ow path from the inlet into the rst chamber, downwardly through the first chamber to the connection, through ythe second vchamber upwardly to its outlet, and into said outlet, a second connection between thetwo chambers adjacent their tops, the second connection having its bottom continuously below the bottom of the outlet and below the liquid level 'in' the chambers to establish continuous communication 'between the chambers adjacent their upper ends, said second connection being adapted to'reduce the velocity of the previously described flow path to provide adequate time of retention of material within the two chambers.

2. VThe combination of claim 1 together with REFERENCES CITED The following references are of record in the file of this patent: Y

' UNITED STATES PATENTs Number Name DateV 1,485,623 Mayo Mar. 4, 1924 1,638,869 Moss Aug. 16, 1927 2,364,472' Piatt Dec. 5, 1944 2,367,270

Evans et al.V Jan. 16, 1945 

